Technical Field
The present invention relates to an apparatus for replacing a welding tip. More particularly, the present invention relates to an apparatus for replacing a welding tip, which is capable of automatically changing the welding tip of a spot welding gun.
Background Art
In general, in quantity production for a specific product as in a vehicle product line, spot welding in which a welding part has high stability is chiefly used because the heating time is very short and working speed is fast compared to other welding and residual stress or deformation is small due to a narrow heating range.
Spot welding is welding in which point bonding is performed on a sheet without perforating a hole in the sheet, such as a riveted joint, by generating melting in contact parts using the generation of heat according to electric resistance and bonding the contact parts using pressure.
Spot welding is performed in the state in which a welding gun is mounted on a robot or mounted on a frame installed on the ground. The welding gun includes a body in which a timer, a contactor, a transformer, etc. for welding are embedded, two shanks 1 facing each other, one of which is installed on one end of a lower arm fixed to the lower part of the body and the other of which is installed on one end of an upper arm rotatably installed in the upper part of the body by a hinge shaft, and welding tips 2 which are attached to the respective shanks 1 and at which welding is performed.
FIG. 1 is a diagram illustrating a conventional method of changing the tip of a robot welding gun.
In order to change the tip of a welding gun used in a current vehicle body manufacturing plant for vehicles, the tip is changed using a tool as illustrated in FIG. 1.
That is, in order to change a welding tip, a worker separates the welding tip 2 from the shank 1 of the welding gun using a pipe wrench or a tip-dedicated tool. Furthermore, a worker mounts a new welding tip using a tool, checks the new welding tip, and checks the state of the new welding tip.
When such a welding tip change task is performed, the time taken to replace the welding tip is relatively long because a worker enters the manufacturing line and directly changes the welding tip in a non-operation time.
Furthermore, if a welding tip needs to be replaced when a vehicle body product line operates, the operation must be stopped while a worker replaces the welding tip. Accordingly, there are problems in that productivity is reduced due to this kind of non-operation time and personal expenses attributable to working hours are increased.
Furthermore, the prior art is problematic in that welding quality is deteriorated because the tip of the shank combined with the welding tip is deformed by external force that is generated when the welding tip is separated from the shank of the welding gun using a tool.